#include <stdio.h>

void removeString(char* text, unsigned int a, unsigned int b);

int main()
{
    char text[] = "the wrong son";
    removeString(text, 4, 6);
    printf("%s\n", text);
    return 0;
}

void removeString(char* text, unsigned int a, unsigned int b)
{
    char* ptext = text;
    text += (a - 1);
    ptext += (a + b -1);
    while (*ptext)
    {
        *text = *ptext;
        text++;
        ptext++;
    }
    *text = 0;
}